Activate light scenes via smartphone, retrofit switches, control the heating, record temperature and humidity data or react to them. If you want to add certain smart home functions to your home, you can choose from a wide variety of manufacturers and technologies. In the absence of a uniform standard, there is plenty of choice: The market in the smart home segment is literally flooded. Some manufacturers rely on open standards, while others cook their own soup, link their devices to their clouds and, in addition to high acquisition costs, may even charge monthly fees. Those who rely on open standards, on the other hand, are probably not tied to one manufacturer and its whims. Probably the best-known cross-manufacturer wireless standards for the smart home are, in addition to WiFi, the standards ZigBee and Z-Wave, which have been optimized for the smart home.

ZigBee

ZigBee is an open standard (IEEE 802.15.4) for the wireless communication of SmartHome devices and is primarily used in lighting technology. Open means that the standard does not belong to anyone and can be used by anyone without a license fee. Well-known manufacturers, such as Philips (Hue), Osram (Lightify) or Ikea (TRÅDFRI) use ZigBee as the radio protocol in their smart lighting systems. ZigBee is similar to WLAN, but consumes much less energy and is therefore ideal for small battery-powered devices that provide years of self-sufficient service. ZigBee devices, unlike WLAN, connect directly to each other to increase range and availability: Mesh network. A central control unit is required for control. The frequency used is 2.4GHz worldwide, the range is about 10-15 meters. Available ZigBee devices are mostly inexpensive.

Z-Wave

Z-Wave, similar to ZigBee, is a mesh radio standard for home automation for private apartments and houses. Z-Wave products are developed and manufactured by the Z-Wave Alliance, an association of various manufacturers, accordingly Z-Wave is not an open standard. Z-Wave requires a little more energy than ZigBee, but has a greater range and a variety of supported devices, for example, in contrast to ZigBee also a greater selection in the direction of heating control. A central control unit is required for control. The frequency used is 908.42Mhz in North America and 868.42Mhz in Europe, the range is 100 meters. Available Z-Wave devices are usually more expensive than comparable Zigbee devices.

WLAN / WiFi

WLAN is available in almost every household, but has not been optimized for use in home automation and is therefore not a real standard for home automation. The advantage of WLAN is in the transport of large amounts of data. The main disadvantage of WLAN compared to the optimized radio technologies is the higher power consumption. Not only is WLAN less suitable for battery-powered devices, but if a large number of sensors or actuators are used, the total power consumption in the house adds up, thereby significantly increasing standby power consumption, even if new WiFi standards have been significantly improved here. With only a few actuators, without a central unit, WLAN can still offer a cheap and simple solution and is therefore often used for standalone solutions.

Thread

Thread uses IPv6 addresses and IEEE 802.15.4 as radio standard and is managed by the Thread Group. Thread is now owned by Google after acquiring the original manufacturer Nest. In addition to Thread, Google has also released OpenThread as an open-source implementation of Thread to accelerate development.Thread uses a mesh network for communication and provides support for low-power and battery-operated devices. The advantage of using IP is that devices can be more easily accessed over the local network or Internet: as an example, communicating from a smart phone directly to a device without a corresponding central control unit. Thread also uses the 2.4Ghz frequency band.

Matter

Matter created a uniform standard between the different manufacturers and builds on the already existing connection technologies Thread, WLAN or LAN. The relatively young standard will be available in the first devices from 2022, or certain devices can be subsequently madefit forMatter via a software update .

EnOcean

EnOcean focuses on devices that do not require batteries or external power sources. Through"energy harvesting", a switch, for example, can generate enough energy to send a radio signal through kinetic energy, purely through the mechanical force of pressing the button. EnOcean uses the frequencies 868.3 Mhz for Europe,902 Mhz for North America and 928Mhz for Japan.

Bluetooth

The introduction of Bluetooth Low Energy (BLE) or Bluetooth 5.0 makes Bluetooth an interesting radio standard for smart homes. It is quite possible that Bluetooth will also be used more for home automation in the future.

HomeMatic IP

For the HomeMatic IP - products the radio standard BidCoS developed by eQ-3 AG is used. eQ-3 is a German company and originated from ELV Elektronik AG. HomeMatic devices also connect via a mesh network, the 868 Mhz band is used for data transmission.

Conclusion

The wireless protocols optimized for use in the smart home use a mesh network, have some common features, but are still not directly compatible with each other due to the lack of a standard. For merging the wireless protocols presented here, there are various manufacturers that support other protocols in addition to their protocol. For example, some smart home control panels additionally offer ZigBee as a wireless protocol.

For all those who want to leave the option open for an alternative wireless standard, there are some open source platforms with the help of which it is possible, for example, on a Raspberry Pi or a NAS with appropriate receivers to control various standards from a central computer. What remains when connecting the various wireless standards is that each ecosystem forms its own mesh network, these then do not support each other, but on the contrary, could interfere. An overview of different smart home platforms, as well as a concrete example, can be found in the following article: Smart Home Platform.